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BISCI exam#3


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what is the purpose of mitosis?
cell development, growth and repair of tissues
in mitosis, parent and daughter cells are what
identical unless there is a mutation
in a diploid, the daughter cells have the same?
# of chromosomes as the parent cell
what is the total # of chromosomes in humans?
this is the orderly set of stages that you can predict that occurs b/t the time a eukaryotic cell divides and the time that the cell's 2 daughters cells divide
The Cell Cycle
how many stages are in the cell cycle?
what are the 4 stages of the cell cycle?
90% of the time during hte cell cycle is spent here
what stages take place in interphase?
what is the 1st step?
what goes on in the 1st step at G1?
GROWTH and repair
production of more organelles
in G1, if the DNA is damaged and can't be repaired what happens to it?
it undergoes APOPTOSIS
what is apoptosis?
programmed cell death
what is the 2nd step?
what hapens in the 2nd S step?
why is the S phase so important?
b/c it is where DNA replication occurs
what is the 3rd step?
what happens in the 3rd step of G2?
final preparations for division
in the G2 phase what is hte preparation for division?
protein synthesis
where does protein synthesis occur?
3rd step - G2
What is G2 also called?
"mitosis checkpoint"
what is the next step after interphase is completed?
what % of the time is spent in mitosis?
how long does mitosis last for the organsim?
it's whole life span
where is the mitosis check point located?
after metaphase
what occurs at mitosis checkpoint?
centrosomes allign down the ceter, it is called the "spindle assembly checkpopint"
a duplicated chromosome contains:
- 2 sister chromatids
- each of these sister chromatids has copies of the same genes
what joins the chromatids of the chromosome?
two chromatids side by side are called what?
sister chromatids
what attatches to the spindle fibers?
the kinetochore
what is the 1st phase of mitosis?
what happens in EARLY PROPHASE?
- nucleolus disappears
- nuclear envelope is fragmenting
whatis the 2nd phase of mitosis?
what happens in PROPHASE?
- chromatids and centomere are created
- spindle fibers form
what is the 3rd phase of mitosis?
what happens in PROMETAPHASE?
- the spindle fibers attatch to the kenetochores of each chromatid
- polar spindle fibers stretch and overlap
what is the 4th phase of mitosis?
what happens in METAPHASE?
- all centromeres are alligned
what is the 5th phase of mitosis?
what happens in ANAPHASE?
sister chromatids become daughter chromosomes and move toward the spindle poles
what is the final phase of mitosis?
what happens in TELOPHASE?
- new nuclei are produced
- spindle fibers vanish
- daughter cells are formed
what do stem cells always have the ability to do?
where is a rich site of stem cells?
red bone marrow
even _____ has stem cells
body fat
during cancer, the cell cycle
flys out of control, hence mitosis is out of control
this is abnormal cell growth when you have this, you are forming a tumor
this type of tumor is encapsulated, it is still abnormal cell growth yet it isn't harmful
benign tumor
this type of tumor isn't encapsulated and it spreads out of control, it is cancerous
malignant tumor
this is a mutation of the genes of the regulatore of the cell cycle
what does genesis mean?
" formation of"
what is carcenogenesis?
the formation of cancer cells
normally every cell in the tissue has a job to preform and a purpose, but in carcenogenesis...
one cell is different and it has no job or purpose, so it just creates tumors
why isn't this "different cell" destroyed?
b/c it has an abnormal nuclei that makes them bipass apoptosis (programmed cell death)
if one was to say that hte cancer cell is mastastisized, what does that mean?
that the cancer cell is spreading
what is another origin of the cancer cell?
a faulty DNA repair system
mitosis is A-sexual
mitosis is A-sexual
what 2 organisms live in extrmem conditions and have A-sexual reproduction
bacteria and archea
in the growth factor, where are the external signals received?
at the plasma membrane
what do signal molecules do?
they either stimulate or inhibit molecular event
what are the 2 signal molecules?
stimulatory pathway
inhibitory pathway
what do checkpoints do?
- prevent mutation
- are there for quality control
what does the proto-oncogene do?
promotes the cell cycle producing more cell divison
- it deals with the stimulatory pathway
what is the proto-oncgene called?
"gas pedal"
what does the tumor suppressor gene do?
slows down the cell division, it deals with the inhibitory pathway
what is the tumor suppressant gene called?
what are the 4 influences that cause mutated proto-oncogenes and suppressor genes?
radiation sources
pesticides and herbicides
what are 2 prokaryotes?
bacteria and archea
what type of cell division does the prokaryotic bacteria and archea undergo?
binary fission
what is the function of the prokaryotic bacteria and archea?
A-sexual reproduction
what are 2 eukaryotes?
protists and some fungi
what type of cell division does the eukaryotic protists and fungi undergo?
mitosis and cytokinesis
what type of cell division does the eukaryotic plants and animals undergo?
mitosis and cytokinesis
what is the function of eukaryotic plants and animals?
binary fission
division that produces two daughter cells that are identical to the parent cell
what are the simple steps of binary fission?
1- DNA replicates
2- cell lengthens
3- the 2 chromosomes seperate
4- the cells become divided
5- result is 2 identical cells
what is the purpose of Meiosis?
sexual reproduction, for continuing the species
what does a haploid consist of?
23 pairs of chromosomes
what does a diploid consist of?
46 pairs of chromosomes
in Meiosis, you start with what?
2 Gametes (sperm + egg cell)
in Meiosis, what do the 2 gametes fuze to form?
a zygote
how many nuclear divisions occur in meiosis?
in diploid body cells, chromosomes occur in pairs called what?
homologous pairs
explain a homologous pair
you can have genes for the same trait, but have different applications such as both applications are for hair,but one can be blonde and one can be brown
what are alternate forms of the same gene ?
such as red hair:black hair
what occurs first during meiosis 1?
the homologous chromosomes pair up
what occurs second during meiosis 1?
nuceloprotein lattice develops b/t the chromosomes
what does the nucleoprotein lattice do?
it zippers the members of the bivalent together so that corresponding genes are in allignment
what do Chiasmata indicate?
where crossing over has occured
what happens when the chromatids cross over?
they exchange genetic material
in what way do the genetic materials swap?
what does the random swap promote?
variation in specific traits
what is a bivalent?
a pair of chromosomes
In Meiosis 1 ... what is the first phase?
prophase 1
what happens in prophase 1?
Homologous chromosomes pair during synapsis and crossing-over occurs
what is synapsis?
the forming of a homologous pair
In Meiosis 1 ... what is the second phase?
Metaphase 1
what happens in metaphase 1?
homologous pairs allign, there are bivalent pairs
In Meiosis 1, what is the third phase?
Anaphase 1
wat happens in Anaphase 1?
homolgous pairs seperate
In Meiosis 1, what is the fourth phase?
Telophase 1
what happens in Telophase 1?
there are 2 distinctie nuclei
In Meiosis 1, what is the final phase?
what happens in Interkinesis?
there are 2 cells
n=2 n=2
what is another name for Interkinesis?
In Meiosis II, what is the first phase?
Prophase II
what happens in prophase II?
the envelope is breaking down, cells have one chromosome from each homologous pair
In Meiosis II, what is the second phase?
Metaphase II
what happens in Metaphase II?
chromosomes allign in single file (going down)
In Meiosis II, what is the third phase?
Anaphase II
what happens in Anaphase II?
Sister chromatids seperate and become daughter chromosomes
In Meiosis II, what is the fourth phase?
Telophase II
what happens in Telophase II?
spindles disappear
nuclei form
cytokinesis takes place
what is the final result of Meiosis II ?
4 haploid daughter clls
how do we form gametes?
by meiosis
what is produced after Mitosis?
Mitosis = 2 haloid cells

Meiosis = 4 haploid cells
meiosis keeps the chromosome # ________
Meiosis promotes______________
genetic variation
wat is the general term for the process of "crossing over" and "swapping genetic material"?
Genetic Recombination
what does Genetic Recombination cause?
variation in specific traits , it is a random swap!!
what is independant assortment?
homologous pairs seperate randomly,
8 million possible variations!!
what are the fertilization stats?
take the 8 milion possibilities from independant assortment and square it (5x10^27) - extremely large number!
howmany diploid cells does Mitosis have?
Mitosis = 2 diploid cells
Meiosis = 4 haploid cells
Mitosis daughter cells are _______ to the parent, Meiosis daughter cells are ______ to the parent.
Mitosis = idetical to parent

Meiosis = different from parent
how many nuclear divisions in Mitosis?
Mitosis = 1 nuclear division

Meiosis = 2 nuclear divisions
what are Meiosis's 2 nuclear divisions called?
Meiosis I
Meiosis II
what type of function does Mitosis have? Meiosis?
Mitosis = A-sexual

Meiosis = sexual
how many chromosome pais does Mitosis have? Meiosis?
Mitosis = 46

Meiosis = 23
what is the difference in how animals and plants have sexual reproduction?
in animals and plants...

-haploid forms spores
-zygote is produced(diploid)
-the generations go like this: haploid,diploid,haploid,diploid
Meiosis = haploid (n)
Mitosis = diploid (2n)
Mitosis occurs all life long time
Meiosis occurs only during child bearing age in females 9 selective)
what is the difference between the Metaphase of Mitosis and the Metaphase I of Meiosis?
Metaphase (Mitosis) = the chromosomes line up like this
Metaphase I (Meosis) = the chromosomes line up like this
what is the difference between the anaphase of Mitosis and the anaphase I of Meiosis?
anaphase (Mitosis) = the sister chromatids separate and become daughter chromosomes
anaphase I (Meosis) = the homologous pairs separate and move towards poles
WHat does Spermatogenesis produce?
4 viable sperm
what does oogenesis produce?
one egg and at least 2 polar bodies
In humans, both sperm and egg each have 23 chromosomes, so following fertilization the zygote has 46 chromosomes
In humans, both sperm and egg each have 23 chromosomes, so following fertilization the zygote has 46 chromosomes
who was the man that did experiments in large numbers?
what are MENDEL's 2 "claims to fame"?
- Particulate Theory of Inheritance
- Law of Segregation
what is the basic idea behind the ancient "Blending Concept of Inheritance" ?
that if you crossed a red and whie flower you would always get a pink flower outcome
what is the idea behnd the " Particulate Theory of Inheritence" ?
-reshuffling of same genes
-basic hereditary unit is the gene
what is the basic heredity unit?
the gene
What is the basic idea behind the "Law of Segregation" ?
-separation of the trais ( not just pink flower outcomes, some could be all white or all red) they weren't all blended into pink
these are alternate forms of the gene that controls a specific trait (such as tall or short)
what are the 2 types of alleles?
Dominant and Recessive
what does the Dominant look like?
TT or Tt

(they are both "tall plants")
what does the recessive look like?

("short plant")
what does Homozygous mean?
what does Heterozygous mean?
what does Homozygous look like?
TT or tt
what does Heterozygous look like?
where is a genotype foun?
a plant
what does the genotype show?
it shows the gene that is ACTUALLY THERE
example of Genotype:
( they are both tall but the genotype shows wha they actually are)
where is the Phenotype seen in?
what is the phenotype?
the outter appearance ( it's either dominant or recessive
example of Phenotype:
all you see is a tall plant, you know it's Dominant, but you can't see whether it was TT or Tt ( the phenotype is only what you can see)
in thi punnett square;

E e
E - EE Ee
e - Ee ee

what is the ratio of Homozygous dominant:Heterozygous:homozygous recessive??

EE : Ee,Ee : ee
wat does a one trait test cross look like?
e e
E Ee Ee

e ee ee

(4^n = 4^1)
what does a Dihybrid cross look like?
AB Ab aB ab

Ab AABb AAbb AaBb Aabb

aB AaBB AaBb aaBB aaBb

ab AaBb Aabb aaBb aabb
what are the possible phenotypes and genotypes for the bloodtypes?
O ii
what is an autosome?
any chromsome that is nota sexchromosome
humans have 22 chromosomal pairs and 1 sex pair ( xx
xy )
humans have 22 chromosomal pairs and 1 sex pair ( xx
xy )
what does Autosomal Dominant look like?
AA or Aa
what does autosomal recessive look like?
what are he autosomal recessive diseases?
Tay Sachs
cystic fibrosis
sickle cell disease
what makes sickle cell disease different from all the other autosomal recessive disease?
you can be in the "trait" zone, but still not have the full blown disease
this is when one genetic change affects more then one characteristic of a person
what is an example of pleiotropy?
sickle cell disease
what is the carrier??
the heterozygous autosomla recessive, they don't have the disease but they carry it
Tay Sachs is an
enzyme defficiency in children
wha is prevelence?
total # in population
what is incidence?
new cases per year
what is the autosomal dominant disease?
Huntington disease
what does huntington disease have?
a delayed onset ( it is deterioraing brain cells)
what is it called when the red and the white flower actually did make the pink flower
Incomplete Dominance
what is the most common type of multiple allelic traits?
blood typing
this is when 2 allels team up and share dominance
what is a blood type example of codominance
this inheritance has many degrees and choices
polygenic inheritance
what is polygenic inheritance's specific traits controlled by?
enviroment and 2 or more allels
what is the example given of polygenic inheritance?
skin tone
what is the polygenic disorder
when a person inherits a TENDANCY, not a certainty
what does the polygenic disorder deal with?
genotype and enviroment
what are examples of polygenic disorders?
hypertension, diabetes, caner
what are x-linked disorders?
genes carried on the x chromosome
who are the main carriers of the x-linked disorders?
the females ( XX ) -males are XY
what do the x-linked disorders have to deal with?
the 23 rd chromosome
what are some of the x-linked disorders?
color blind
muscle distrophy
fragile x syndrome which is the 2nd leading cause of mental retardaion
what is the ide behind gene linkage?
that genes can be inheritd together becaus they are linked together in the "linkge group"
what are the causes of offspring variaton?
- crossing over
- recombination of chromosomes during meiosis
- gamete possibilities at fertilization
- chromosomal mutations
what about crossing over?
during early prophase, the genes can be locate4d, they coss over
what about recombination of chromosomes during meiosis?
chromatids go in diff. directions, there is a separation of the chrom. and the recombine
what about gamete possibilities at fertilization?
the particular sperm meets the particular egg
what about chromosomal mutations?
1- changing of number of chomosomes
2- changing of the structre of chromosomes
euploidy =
correct # of chromosomes
polyploidy =
greater than or equal to 3 whole extra sets of chromosome (1-22)
what is polyploidy common in?
what is aneuploidy?
any abnormal increase or decrease of the # of chromosomes
what is monosomy?
missing one chromosome
what is trisomy?
an extra chromosome is present
trisomy-21 =
down syndrom on the 21st chromosome
Turner syndrome =
in females, missing an X chromosome
Klinefelter syndrome =
males, has an extra X chromosome
all autosomal chromosomes are correct, it is the sex chromosome that disease stems from
all autosomal chromosomes are correct, it is the sex chromosome that disease stems from
what are the 3 causes of change in the structure of chromosomes?
-chemical exposure
what is deletion?
missing gene on one or more chromosome
wht is duplication?
repeating same gene sequence on same chromosome
what is inversion?
upside down gene sequence
what is translocation?
moving gene sequence to non-homologous chromosome ( moved from one chromatid to a cmpletely different one

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